An image forming apparatus such as a copying machine, a printer or a facsimile forms an electrostatic latent image on a photosensitive drum and develops the electrostatic latent image with a toner, thereby forming a visible image.
Such an image forming apparatus is provided with a developing apparatus for storing the toner and feeding the same to the photosensitive drum. In general, the developing apparatus transports the toner to the photosensitive drum with a developing roller.
Further, various types of developing apparatuses transporting an electrostatically charged toner to a photosensitive drum through the action of an electric field are proposed.
When the toner is transported through the action of an electric field, friction caused on the transported toner can be reduced, and deterioration of the toner can be suppressed.
However, the toner cannot be transported through the electric field unless the same is precharged even using the above-mentioned transportation method. Precharging inevitably results in friction, and hence the toner is disadvantageously somewhat deteriorated.